http://precedings.nature.com/users/8dce83dc36785f305fd268e651b75dac/ Documents posted by Venkaiah Betapudi Nature Publishing Group en Nature Precedings http://precedings.nature.com/images/header_logo.gif http://precedings.nature.com http://precedings.nature.com/documents/2868/version/1 Non-muscle myosin II role has been implicated in the extension of lamellipodia, a critical step in the initiation of directed cell migration, invasion and other cellular processes, but the mechanistic details are limited to driving retrograde actin filaments. The present study reveals distinct localization of myosin IIA and IIB with an unexpected opposite mechanical roles in mediating lamellipodia extension during spreading. Attachment of cells to matrix is impaired in the absence of either isoforms, but differential regulation of focal contacts formation occurs in myosin IIA-; and IIB-; cells. Spreading cells expressing both isoforms display an organized actin network consisting of retrograde filaments, arcs and central filaments. Loss of actin arcs and central filaments occurs upon depletion of either myosin IIA or IIB, but myosin IIB-; cells displayed long parallel actin filaments elongated from cell edge. From these studies, a model for myosin IIA and IIB with separate, but linked mechanical roles in mediating lamellipodia extension is developed. http://precedings.nature.com/documents/2868/version/1 Wed, 18 Feb 2009 19:24:53 UTC Myosin II isoforms with separate but linked functions determine the fate of lamellipodia extension during cell spreading hdl:10101/npre.2009.2868.1 2009-02-18 Venkaiah Betapudi Nature Precedings 2009-02-18T19:24:53Z Manuscript Cancer Microbiology Molecular Cell Biology http://creativecommons.org/licenses/by/3.0/